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4434 Invistigation of Surface Properties of Nanostructured Carbon Films
Authors: Narek Margaryan, Zhozef Panosyan
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Due to their unique properties, carbon nanofilms have become the object of general attention and intensive research. In this case it plays a very important role to study surface properties of these films. It is also important to study processes of forming of this films, which is accompanied by a process of self-organization at the nano and micro levels. For more detailed investigation, we examined diamond-like carbon (DLC) layers deposited by chemical vapor deposition (CVD) method on Ge substrate and hydro-generated grapheme layers obtained on surface of colloidal solution using grouping method. In this report surface transformation of these CVD nanolayers is studied by atomic force microscopy (AFM) upon deposition time. Also, it can be successfully used to study surface properties of self-assembled grapheme layers. In turn, it is possible to sketch out their boundary line, which enables one to draw an idea of peculiarities of formation of these layers. Images obtained by AFM are investigated as a mathematical set of numbers and fractal and roughness analysis were done. Fractal dimension, Regne’s fractal coefficient, histogram, Fast Fourier transformation, etc. were obtained. The dependence of fractal parameters on the deposition duration for CVD films and on temperature of solution tribolayers was revealed. As an important surface parameter for our carbon films, surface energy was calculated as function of Regne’s fractal coefficient. Surface potential was also measured with Kelvin probe method using semi-contacting AFM. The dependence of surface potential on the deposition duration for CVD films and on temperature of solution for hydro-generated graphene was found as well. Results obtained by fractal analysis method was related with purly esperimental results for number of samples.Keywords: nanostructured films, self-assembled grapheme, diamond-like carbon, surface potential, Kelvin probe method, fractal analysis
Procedia PDF Downloads 2684433 Larger Diameter 22 MM-PDC Cutter Greatly Improves Drilling Efficiency of PDC Bit
Authors: Fangyuan Shao, Wei Liu, Deli Gao
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With the increasing speed of oil and gas exploration, development and production at home and abroad, the demand for drilling speed up technology is becoming more and more critical to reduce the development cost. Highly efficient and personalized PDC bit is important equipment in the bottom hole assembly (BHA). Therefore, improving the rock-breaking efficiency of PDC bits will help reduce drilling time and drilling cost. Advances in PDC bit technology have resulted in a leapfrogging improvement in the rate of penetration (ROP) of PDC bits over roller cone bits in soft to medium-hard formations. Recently, with the development of PDC technology, the diameter of the PDC tooth can be further expanded. The maximum diameter of the PDC cutter used in this paper is 22 mm. According to the theoretical calculation, under the same depth of cut (DOC), the 22mm-PDC cutter increases the exposure of the cutter, and the increase of PDC cutter diameter helps to increase the cutting area of the PDC cutter. In order to evaluate the cutting performance of the 22 mm-PDC cutter and the existing commonly used cutters, the 16 mm, 19 mm and 22 mm PDC cutter was selected put on a vertical turret lathe (VTL) in the laboratory for cutting tests under different DOCs. The DOCs were 0.5mm, 1.0 mm, 1.5 mm and 2.0 mm, 2.5 mm and 3 mm, respectively. The rock sample used in the experiment was limestone. Results of laboratory tests have shown the new 22 mm-PDC cutter technology greatly improved cutting efficiency. On the one hand, as the DOC increases, the mechanical specific energy (MSE) of all cutters decreases, which means that the cutting efficiency increases. On the other hand, under the same DOC condition, the larger the cutter diameter is, the larger the working area of the cutter is, which leads to higher the cutting efficiency. In view of the high performance of the 22 mm-PDC cutters, which was applied to carry out full-scale bit field experiments. The result shows that the bit with 22mm-PDC cutters achieves a breakthrough improvement of ROP than that with conventional 16mm and 19mm cutters in offset well drilling.Keywords: polycrystalline diamond compact, 22 mm-PDC cutters, cutting efficiency, mechanical specific energy
Procedia PDF Downloads 2044432 Raman Spectroscopic of Cardioprotective Mechanism During the Metabolic Inhibition of Heart Cells
Authors: A. Almohammedi, A. J. Hudson, N. M. Storey
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Following ischaemia/reperfusion injury, as in a myocardial infraction, cardiac myocytes undergo oxidative stress which leads to several potential outcomes including; necrotic or apoptotic cell death or dysregulated calcium homeostasis or disruption of the electron transport chain. Several studies have shown that nitric oxide donors protect cardiomyocytes against ischemia and reperfusion. However until present, the mechanism of cardioprotective effect of nitric oxide donor in isolated ventricular cardiomyocytes is not fully understood and has not been investigated before using Raman spectroscopy. For these reasons, the aim of this study was to develop a novel technique, pre-resonance Raman spectroscopy, to investigate the mechanism of cardioprotective effect of nitric oxide donor in isolated ventricular cardiomyocytes exposed to metabolic inhibition and re-energisation. The results demonstrated the first time that Raman microspectroscopy technique has the capability to monitor the metabolic inhibition of cardiomyocytes and to monitor the effectiveness of cardioprotection by nitric oxide donor prior to metabolic inhibition of cardiomyocytes. Metabolic inhibition and reenergisation were used in this study to mimic the low and high oxygen levels experienced by cells during ischaemic and reperfusion treatments. A laser wavelength of 488 nm used in this study has been found to provide the most sensitive means of observe the cellular mechanisms of myoglobin during nitric oxide donor preconditioning, metabolic inhibition and re-energisation and did not cause any damage to the cells. The data also highlight the considerably different cellular responses to metabolic inhibition to ischaemia. Moreover, the data has been shown the relationship between the release of myoglobin and chemical ischemia where that the release of myoglobin from the cell only occurred if a cell did not recover contractility.Keywords: ex vivo biospectroscopy, Raman spectroscopy, biophotonics, cardiomyocytes, ischaemia / reperfusion injury, cardioprotection, nitric oxide donor
Procedia PDF Downloads 3524431 The Effect of Colloidal Metals Nanoparticles on Quarantine Bacterium - Clavibacter michiganensis Ssp. sepedonicus
Authors: Włodzimierz Przewodowski, Agnieszka Przewodowska
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Colloidal metal nanoparticles have drawn increasing attention in the field of phytopathology because of their unique properties and possibilities of applications. Their antibacterial activity, no induction of the development of pathogen resistance and the ability to penetrate most of biological barriers make them potentially useful in the fighting against dangerous pathogens. These properties are very important in the case of protection of strategic crops in the world, like potato - fourth crop in the world - which is host to numerous pathogenic microorganisms causing serious diseases, significantly affecting yield and causing the economic losses. One of the most important and difficult to reduce pathogen of potato plant is quarantine bacterium Clavibacter michiganensis ssp. sepedonicus (Cms) responsible for ring rot disease. Control and detection of these pathogens is very complicated. Application of healthy, certified seed material as well as hygiene in potato production and storage are the most efficient ways of preventing of ring rot disease. Currently used disinfectants and pesticides, have many disadvantages, such as toxicity, low efficiency, selectivity, corrosiveness, and the inability to eliminate the pathogens in potato tissue. In this situation, it becomes important to search for new formulations based on components harmful to health, yet efficient, stable during prolonged period of time and a with wide range of biocide activity. Such capabilities are offered by the latest generation of biocidal nanoparticles such as colloidal metals. Therefore the aim of the presented research was to develop newly antibacterial preparation based on colloidal metal nanoparticles and checking their influence on the Cms bacteria. Our preliminary results confirmed high efficacy of the nano-colloids in controlling the this selected pathogen.Keywords: clavibacter michiganensis ssp. sepedonicus, colloidal metal nanoparticles, phytopathology, bacteria
Procedia PDF Downloads 2724430 Recent Developments and Expectations in the Legal Expenses Insurance in Turkey
Authors: İbrahim Arslan, Mücahit Ünal
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An important issue to ensure justice is to simplify the right to seek justice. But there is a cost of seeking justice in civil law. It costs at least, attorneys' fees and judicial expenses during the beginning and in case of losing a trial. Indeed, most of the people refrain from seeking justice because of these expenses. Therefore, it is not inappropriate to say that the removal of obstacles staying on the way of seeking justice will increase the belief in justice. Legal expenses insurance is a private law contract of insurance in which the insurer is obliged to pay premiums of the insured, to provide the necessary services for the protection of legal interests of the insured person within the agreed scope. This type of insurance is being practiced in the Western world for a long time. The special rights, duties and obligations of the parties to a legal expenses insurance contract shall be governed by the Turkish Commercial Code (TCC) and the contractual agreements which are regularly closed in the form of general terms and conditions. If the number of the legal expenses insurance contracts concluded increase this will definitely improve the percentage of seeking justice before the courts. The general terms and conditions applicable in Turkey generally include litigation costs, referee fees, guarantee fund , enforcement costs , appeal costs borne decision corrections costs. In addition, besides the insured, other family members or the people specified in the policy are protected in the scope of personal/family legal expenses insurance. The commercial law disputes fall outside the scope of coverage in this insurance branch. The insured person chooses his own lawyer and the insurer is not allowed to give advice during the selection of a lawyer. In April 2015, the Prime Minister announced of a new era in the field of legal expenses insurance in Turkey and this announcement excited the insurance industry and legal community.Keywords: insurance, in the Turkish law on legal protection insurance, legal protection insurance, legal protection
Procedia PDF Downloads 3574429 Economic Effects of Maritime Environmental Legislation in the North and Baltic Sea Area: An Exploratory Sequential Mixed Methods Approach
Authors: Thea Freese
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Environmental legislation to protect North and Baltic Sea areas from harmful vessel-source emissions has received increased political attention in recent years. Legislative measures are expected to show positive effects on the health of the marine environment and society. At the same time, compliance might increase the costs to industry and have effects on freight rates and volumes shipped with potential negative repercussions on the environment. Building on an exploratory sequential mixed methods approach, this research project will study the economic effects of maritime environmental legislation in two phases. In Phase I, exploratory in-depth interviews were conducted with 12 experts from various stakeholder groups aiming at identifying variables influencing the relationship between environmental legislation, freight rates and volumes shipped. Influencing factors like compliance, enforcement and modal shift were identified and studied. Phase II will comprise of a quantitative study conducted with the aim of verifying the theory build in Phase I and quantifying economic effects of rules on shipping pollution. Research in this field might inform policy-makers about determinants of behaviour of ship operators in the face of the law and might further the development of a comprehensive legal system for marine environmental protection. At the present stage of research, first tentative results from the qualitative phase may be examined and open research questions to be addressed in the quantitative phase as well as possible research designs for phase II may be discussed. Input from other researchers will be highly valuable at this point.Keywords: clean shipping operations, compliance, maritime environmental legislation, maritime law and economics, mixed methods research, North and Baltic Sea area
Procedia PDF Downloads 3764428 A Review of Current Practices in Tattooing of Colonic Lesion at Endoscopy
Authors: Dhanashree Moghe, Roberta Bullingham, Rizwan Ahmed, Tarun Singhal
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Aim: The NHS Bowel Screening Programme recommends the use of endoscopic tattooing for suspected malignant lesions that later require surgical or endoscopic localisation, using local protocols as guidance. This is in accordance with guidance from the BSG (The British Society of Gastroenterologists). We used a well-recognised local protocol as a standard to audit current tattooing practice in a large district general hospital with no current local guidelines. Method: A retrospective quantitative analysis of 50 patients who underwent segmental colonic resection for cancer over a 6-month period in 2021. We reviewed historic electronic endoscopy reports recording relevant data on tattoo indication and placement. Secondly, we carried out an anonymous survey of 16 independent lower GI endoscopists on self-reported details of their practice. Results: In our study, 28 patients (56%) had a tattoo placed at the time of their colonoscopy. Of these, only 53% (n=15) had the tattoo distal to the lesion, with the measured distance of the tattoo from the lesion only being documented in 8 reports. Only seven patients (25%) had a circumferential (4 quadrant) placement of the tattoo. 13 patients had lesions either in the caecum or rectum, locations deemed unnecessary as per BSG guidelines. Of the survey responses collected, there were four different protocols being used to guide practice. Only 50% of respondents placed tattoos at the correct distance from the lesion, and 83% placed the correct number of tattoos. Conclusion: There is a lack of standardisation of practices in colonic tattooing demonstrated in our study with incomplete compliance to our standard. The inadequate documentation of tattoo location can contribute to confusion and inaccuracy in the intraoperative localisation of lesions. This has the potential to increase operation length and morbidity. There is a need to standardise both technique and documentation in colonoscopic tattooing practice.Keywords: colorectal cancer, endoscopic tattooing, colonoscopy, NHS BSCP
Procedia PDF Downloads 1204427 Investigation of the Properties of Epoxy Modified Binders Based on Epoxy Oligomer with Improved Deformation and Strength Properties
Authors: Hlaing Zaw Oo, N. Kostromina, V. Osipchik, T. Kravchenko, K. Yakovleva
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The process of modification of ed-20 epoxy resin synthesized by vinyl-containing compounds is considered. It is shown that the introduction of vinyl-containing compounds into the composition based on epoxy resin ED-20 allows adjusting the technological and operational characteristics of the binder. For improvement of the properties of epoxy resin, following modifiers were selected: polyvinylformalethyl, polyvinyl butyral and composition of linear and aromatic amines (Аramine) as a hardener. Now the big range of hardeners of epoxy resins exists that allows varying technological properties of compositions, and also thermophysical and strength indicators. The nature of the aramin type hardener has a significant impact on the spatial parameters of the mesh, glass transition temperature, and strength characteristics. Epoxy composite materials based on ED-20 modified with polyvinyl butyral were obtained and investigated. It is shown that the composition of resins based on derivatives of polyvinyl butyral and ED-20 allows obtaining composite materials with a higher complex of deformation-strength, adhesion and thermal properties, better water resistance, frost resistance, chemical resistance, and impact strength. The magnitude of the effect depends on the chemical structure, temperature and curing time. In the area of concentrations, where the effect of composite synergy is appearing, the values of strength and stiffness significantly exceed the similar parameters of the individual components of the mixture. The polymer-polymer compositions form their class of materials with diverse specific properties that ensure their competitive application. Coatings with high performance under cyclic loading have been obtained based on epoxy oligomers modified with vinyl-containing compounds.Keywords: epoxy resins, modification, vinyl-containing compounds, deformation, strength properties
Procedia PDF Downloads 1124426 A Conceptual Framework for Vulnerability Assessment of Climate Change Impact on Oil and Gas Critical Infrastructures in the Niger Delta
Authors: Justin A. Udie, Subhes C. Bhatthacharyya, Leticia Ozawa-Meida
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The impact of climate change is severe in the Niger Delta and critical oil and gas infrastructures are vulnerable. This is partly due to lack of specific impact assessment framework to assess impact indices on both existing and new infrastructures. The purpose of this paper is to develop a framework for the assessment of climate change impact on critical oil and gas infrastructure in the region. Comparative and documentary methods as well as analysis of frameworks were used to develop a flexible, integrated and conceptual four dimensional framework underpinning; 1. Scoping – the theoretical identification of inherent climate burdens, review of exposure, adaptive capacities and delineation of critical infrastructure; 2. Vulnerability assessment – presents a systematic procedure for the assessment of infrastructure vulnerability. It provides real time re-scoping, practical need for data collection, analysis and review. Physical examination of systems is encouraged to complement the scoped data and ascertain the level of exposure to relevant climate risks in the area; 3. New infrastructure – consider infrastructures that are still at developmental level. It seeks to suggest the inclusion of flexible adaptive capacities in original design of infrastructures in line with climate threats and projections; 4. The Mainstreaming Climate Impact Assessment into government’s environmental decision making approach. Though this framework is designed specifically for the estimation of exposure, adaptive capacities and criticality of vulnerable oil and gas infrastructures in the Niger Delta to climate burdens; it is recommended for researchers and experts as a first-hand generic and practicable tool which can be used for the assessment of other infrastructures perceived as critical and vulnerable. The paper does not provide further tools that synch into the methodological approach but presents pointers upon which a pragmatic methodology can be developed.Keywords: adaptation, assessment, conceptual, climate, change, framework, vulnerability
Procedia PDF Downloads 3174425 Exploring Students' Alternative Conception in Vector Components
Authors: Umporn Wutchana
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An open ended problem and unstructured interview had been used to explore students’ conceptual and procedural understanding of vector components. The open ended problem had been designed based on research instrument used in previous physics education research. Without physical context, we asked students to find out magnitude and draw graphical form of vector components. The open ended problem was given to 211 first year students of faculty of science during the third (summer) semester in 2014 academic year. The students spent approximately 15 minutes of their second time of the General Physics I course to complete the open ended problem after they had failed. Consequently, their responses were classified based on the similarity of errors performed in the responses. Then, an unstructured interview was conducted. 7 students were randomly selected and asked to reason and explain their answers. The study results showed that 53% of 211 students provided correct numerical magnitude of vector components while 10.9% of them confused and punctuated the magnitude of vectors in x- with y-components. Others 20.4% provided just symbols and the last 15.6% gave no answer. When asking to draw graphical form of vector components, only 10% of 211 students made corrections. A majority of them produced errors and revealed alternative conceptions. 46.5% drew longer and/or shorter magnitude of vector components. 43.1% drew vectors in different forms or wrote down other symbols. Results from the unstructured interview indicated that some students just memorized the method to get numerical magnitude of x- and y-components. About graphical form of component vectors, some students though that the length of component vectors should be shorter than those of the given one. So then, it could be combined to be equal length of the given vectors while others though that component vectors should has the same length as the given vectors. It was likely to be that many students did not develop a strong foundation of understanding in vector components but just learn by memorizing its solution or the way to compute its magnitude and attribute little meaning to such concept.Keywords: graphical vectors, vectors, vector components, misconceptions, alternative conceptions
Procedia PDF Downloads 1894424 Degradation of Petroleum Hydrocarbons Using Pseudomonas Aeruginosa Isolated from Oil Contaminated Soil Incorporated into E. coli DH5α Host
Authors: C. S. Jeba Samuel
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Soil, especially from oil field has posed a great hazard for terrestrial and marine ecosystems. The traditional treatment of oil contaminated soil cannot degrade the crude oil completely. So far, biodegradation proves to be an efficient method. During biodegradation, crude oil is used as the carbon source and addition of nitrogenous compounds increases the microbial growth, resulting in the effective breakdown of crude oil components to low molecular weight components. The present study was carried out to evaluate the biodegradation of crude oil by hydrocarbon-degrading microorganism Pseudomonas aeruginosa isolated from natural environment like oil contaminated soil. Pseudomonas aeruginosa, an oil degrading microorganism also called as hydrocarbon utilizing microorganism (or “HUM” bug) can utilize crude oil as sole carbon source. In this study, the biodegradation of crude oil was conducted with modified mineral basal salt medium and nitrogen sources so as to increase the degradation. The efficacy of the plasmid from the isolated strain was incorporated into E.coli DH5 α host to speed up the degradation of oil. The usage of molecular techniques has increased oil degradation which was confirmed by the degradation of aromatic and aliphatic rings of hydrocarbons and was inferred by the lesser number of peaks in Fourier Transform Infrared Spectroscopy (FTIR). The gas chromatogram again confirms better degradation by transformed cells by the lesser number of components obtained in the oil treated with transformed cells. This study demonstrated the technical feasibility of using direct inoculation of transformed cells onto the oil contaminated region thereby leading to the achievement of better oil degradation in a shorter time than the degradation caused by the wild strain.Keywords: biodegradation, aromatic rings, plasmid, hydrocarbon, Fourier Transform Infrared Spectroscopy (FTIR)
Procedia PDF Downloads 3724423 Land Use Dynamics of Ikere Forest Reserve, Nigeria Using Geographic Information System
Authors: Akintunde Alo
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The incessant encroachments into the forest ecosystem by the farmers and local contractors constitute a major threat to the conservation of genetic resources and biodiversity in Nigeria. To propose a viable monitoring system, this study employed Geographic Information System (GIS) technology to assess the changes that occurred for a period of five years (between 2011 and 2016) in Ikere forest reserve. Landsat imagery of the forest reserve was obtained. For the purpose of geo-referencing the acquired satellite imagery, ground-truth coordinates of some benchmark places within the forest reserve was relied on. Supervised classification algorithm, image processing, vectorization and map production were realized using ArcGIS. Various land use systems within the forest ecosystem were digitized into polygons of different types and colours for 2011 and 2016, roads were represented with lines of different thickness and colours. Of the six land-use delineated, the grassland increased from 26.50 % in 2011 to 45.53% in 2016 of the total land area with a percentage change of 71.81 %. Plantations of Gmelina arborea and Tectona grandis on the other hand reduced from 62.16 % in 2011 to 27.41% in 2016. The farmland and degraded land recorded percentage change of about 176.80 % and 8.70 % respectively from 2011 to 2016. Overall, the rate of deforestation in the study area is on the increase and becoming severe. About 72.59% of the total land area has been converted to non-forestry uses while the remnant 27.41% is occupied by plantations of Gmelina arborea and Tectona grandis. Interestingly, over 55 % of the plantation area in 2011 has changed to grassland, or converted to farmland and degraded land in 2016. The rate of change over time was about 9.79 % annually. Based on the results, rapid actions to prevail on the encroachers to stop deforestation and encouraged re-afforestation in the study area are recommended.Keywords: land use change, forest reserve, satellite imagery, geographical information system
Procedia PDF Downloads 3564422 The Significance of Ernest Hemingway's Writing Style in the Development of Georgian Prose of 1950-1960s
Authors: Natia Kvachakidze
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The given research aims to study and analyze the influence of Ernest Hemingway’s writing style on Georgian prose of 1950s and 1960s. It is universally known that Ernest Hemingway’s unique writing style has had an enormous effect on various writers. His work remains highly relevant and influential even today. This is especially true about the works written in English, but literary prose created in other languages is not an exception. Certain stylistic peculiarities characteristic for Hemingway’s writing can be traced in literary works written in various languages. It is particularly interesting for us, Georgians, how all these aspects were reflected in Georgian prose of the second-half of XX century. This particular paper (which is a part of a larger research) focuses on major significant peculiarities of Georgian prose of 1950-1960s that might be connected to Hemingway's writing. In this respect, GuramRcheulishvili’s (1934-1960) works should be particularly distinguished (especially his short fiction), but literary works of other Georgian authors are not at all less important. The research involves the analysis of the prose works of some Georgian writers of the given period in the context of tracing similarities and parallels between them and the characteristic features of Ernest Hemingway’s writing style. The use of everyday language as well as short and simple sentences, a concise and sparse style, repetitions, intense dialogues are some of the essential traits in question. Themes like birth and death, war and violence, family, nature, disillusionment also prove to be vitally important for this research. Complex interconnections between the author, the narrator, and the protagonist (often autobiographical) provide another interesting subject to study. At the same time, this paper aims at studying and revealing how Hemingway’s method was reflected and transformed in Georgian prose. In this respect, it is interesting to trace not only the direct effect of Hemingway’s style but also the role of certain Georgian translations of the works of this American writer.Keywords: hemingway, prose, georgian writers, writing style
Procedia PDF Downloads 1794421 Factors Influencing Fertility Preferences and Contraceptive Use among Reproductive Aged Married Women in Eastern Ethiopia
Authors: Heroda Gebru, Berhanu Seyoum, Melake Damena, Gezahegn Tesfaye
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Background: In Ethiopia there is a population policy aimed at reducing fertility and increasing contraceptive prevalence. Objective: To assess the fertility preference and contraceptive use status of married women who were living in Dire Dawa administrative city. Methods: Cross sectional study which included a sample size of 421 married women of reproductive age were performed. Data was collected using structured questionnaire during house to house survey and semi-structured questionnaire during in-depth interview. Data was processed and analyzed using SPSS version 16 computer software. Univariate, bi variate and multi variate analysis was employed. Results: A total of 421 married women of reproductive age group were interviewed having a response rate of 100 percent. More than half (58.2%) of the respondent have desire of more children. While 41.8% want no more children. Regarding contraceptive use 52.5% of the respondents were using contraceptive at the time of survey. Fertility preference and contraceptive use were significantly associated with age of the respondent, history of child death, number of living children, religion and age at first birth. Conclusions: Those women with younger age group, who had no child death history and women with lesser number of surviving children were more likely desire additional children. Women with older age at first birth and protestant in religion were more likely practiced contraceptive use. Strong information and education regarding contraceptive for younger age group should be provided, advocacy at level of religious leader is important, comprehensive family planning counselling and education should be available for the community, husbands, and religious leaders and the aim for increasing contraceptive use should focus on the practical aspect.Keywords: fertility preference, contraceptive use, univariate analysis, family planning
Procedia PDF Downloads 3794420 Associations of Vitamin D Receptor Polymorphisms with Coronary Artery Diseases
Authors: Elham Sharif, Nasser Rizk, Sirin Abu Aqel, Ofelia Masoud
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Background: Previous studies have investigated the association of rs1544410, rs7975232 and rs731236 polymorphisms in vitamin D receptor gene and its impact on diseases such as cancer, diabetes and hypertension in different ethnic backgrounds. Aim: The aim of this study is to investigate the association between VDR polymorphisms using three SNP’s (rs1544410, rs7975232 and rs731236) and the severity of the significant lesion in coronary arteries among angiographically diagnosed CAD. Methods: A prospective-retrospective study was conducted on 192 CAD patients enrolled from the cardiology department-Heart Hospital HMC, grouped in 96 subjects with significant stenosis and 96 with non-significant stenosis with a mean age between 30 and 75 years old. Genotyping was performed for the following SNPs rs1544410, rs7975232 and rs731236 using TaqMan assay by the Real Time PCR, ABI 7500 in Health Sciences Labs at Qatar University Biomedical Research Center. Results: The results showed that both groups have matched age and gender distribution but patients with the significant stenosis have significantly higher; BMI (p=0.047); smoking status (p=0.039); FBS (p= 0.031); CK-MB (p=0.025) and Troponin (p=0.002) than the patients with non–significant lesion. Among the traditional risk factors, smoking increases the odds of the severe stenotic lesion in CAD patients by 1.984, with 95% CI between 1.024 – 7.063, with p= 0.042.HWE showed deviations of the rs1544410 and rs731236 among the study subjects. The most frequent genotype in distribution of rs7975232 is the AA among the significant stenosis patients, while the heterozygous AC was the frequent genotype in distribution among the non-significant stenosis group. The carriers of CC genotype in rs7975232 increased the risk of having significant coronary arteries stenotic lesion by 1.83 with 95% CI (1.020 – 3.280), p=0.043. No association was found between the rs7975232 with vitamin D and VDBP. Conclusion: There is a significant association between rs7975232 and the severity of CAD lesion. The carrier of CC genotype in rs7975232 increased the risk of having significant coronary arteries atherosclerotic lesion especially in patients with smoking history independent of vitamin D.Keywords: vitamin D, vitamin D receptor, polymorphism, coronary harat disease
Procedia PDF Downloads 3124419 Internet Impulse Buying: A Study Based on Stimulus-Organism-Response Theory
Authors: Pui-Lai To, Yi-Jing Tsai
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As the advance of e-commerce technologies, the consumers buying behavior have changed. The focus on consumer buying behavior has already shifted from physical space to the cyberspace, which impulse buying is a major issue of concern. This study examines the stimulus effect of web environment on the consumer's emotional states, and in turn, affecting the urge of impulse buying based on a stimulus-organism-response (S-O-R) theory. Website ambiance and website service quality are the two stimulus variables. The study also explores the effects and the moderator effects of contextual variables and individual characteristic variables on the web environment, the emotional states and the urge of impulse buying. A total of 328 valid questionnaires were collected. Structural equation modeling was used to test the research hypothesis. This study found that both website ambiance and website service quality have a positive effect on consumer emotion, which in turn positively affect the urge of impulse buying. Consumer’s trait of impulse buying has a positive effect on the urge of impulse buying. Consumer’s hedonic motivation has a positive effect on both emotion state and the urge of impulse buying. On the other hand, the study found that money available for the consumer would positively affect consumer's emotion state and time available for the consumer would negatively affect the relationship between website service quality and consumer emotion. The result of this study validates Internet impulse buying behavior based on the S-O-R theory. This study also suggests that having a good website atmosphere and service quality is important to influencing consumers’ emotion and increasing the likelihood of consumer purchasing. The study could serve as a basis for the future research regarding online consumer behavior.Keywords: emotion state, impulse buying, stimulus-organism-response, the urge of impulse buying
Procedia PDF Downloads 2354418 Urgent Care Centres in the United Kingdom
Authors: Mohammad Ansari, Satinder Mann, Ahmed Ismail
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Primary care patients in Emergency Departments (ED) have been the topic of discussion since 1998 in the United Kingdom. Numerous studies have analysed attendances in EDs retrospectively and suggest that at least one third to fifty percent patients attending ED with problems which could be managed appropriately in General Practice or minor injuries units. The pattern of ED Usage seems to be International. In Australia and many departments in the United States include walk in facilities staffed by physicians on family practice residency programme. It clearly appears in the United Kingdom that EDs have to accept that such patients with primary care problems will attend the ED and facilities will have to be provided to see and treat such patients. Urgent care centres were introduced in the United Kingdom nearly a decade ago to reduce the pressure on EDs. Most of these were situated near pre-existing EDs. Unfortunately these centres failed to have the desired effect of reducing the number of patients visiting EDs, it has been noticed that when more patients were seen in Urgent Care centres there were increased attendances in ED as well. A new model of Urgent Care centre was started in the ED of George Eliot Hospital, Nuneaton, UK. We looked at the working of the centre by looking at the number of patients seen daily against the number of total attendances in the ED. We studied the number and type of patients seen by the Urgent Care Doctor. All the medical records of the patients were seen and the time patients spent in the Urgent Care centre was recorded. The total number of patients seen during this study were 1532. 219 (14.3% ) were seen within our Urgent Care centre. None of the patients waited over four hours to be seen. It has been recognised that primary care patients in the ED are a major part of attendances of the department and unless these patients are seen in Urgent Care centres, overcrowding and long waits cannot been avoided. It has been shown that employing primary care Physicians in Urgent Care centres reduces overall cost because they do not carry out as many investigations as Junior Doctors. In our study over 14% patients were seen by Urgent Care Physicians and none of the patients waited for more than four hours and we feel that care provided to the patients by Urgent Care centre was highly effective and satisfying for the patient.Keywords: urgent care centres, primary care physicians, overcrowding, cost
Procedia PDF Downloads 4394417 Delineating Concern Ground in Block Caving – Underground Mine Using Ground Penetrating Radar
Authors: Eric Sitorus, Septian Prahastudhi, Turgod Nainggolan, Erwin Riyanto
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Mining by block or panel caving is a mining method that takes advantage of fractures within an ore body, coupled with gravity, to extract material from a predetermined column of ore. The caving column is weakened from beneath through the use of undercutting, after which the ore breaks up and is extracted from below in a continuous cycle. The nature of this method induces cyclical stresses on the pillars of excavations as stress is built up and released over time, which has a detrimental effect on both the installed ground support and the rock mass itself. Ground support capacity, especially on the production where excavation void ratio is highest, is subjected to heavy loading. Strain above threshold of the elongation of support capacity can yield resulting in damage to excavations. Geotechnical engineers must evaluate not only the remnant capacity of ground support systems but also investigate depth of rock mass yield within pillars, backs and floors. Ground Penetrating Radar (GPR) is a geophysical method that has the ability to evaluate rock mass damage using electromagnetic waves. This paper illustrates a case study from the Grasberg mining complex where non-invasive information on the depth of damage and condition of the remaining rock mass was required. GPR with 100 MHz antenna resolution was used to obtain images of the subsurface to determine rehabilitation requirements prior to recommencing production activities. The GPR surveys were used to calibrate the reflection coefficient response of varying rock mass conditions to known Rock Quality Designation (RQD) parameters observed at the mine. The calibrated GPR survey allowed site engineers to map subsurface conditions and plan rehabilitation accordingly.Keywords: block caving, ground penetrating radar, reflectivity, RQD
Procedia PDF Downloads 1344416 Smart Wheel Chair: A Design to Accommodate Vital Sign Monitoring
Authors: Stephanie Nihan, Jayson M. Fadrigalan, Pyay P. San, Steven M. Santos, Weihui Li
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People of all ages who use wheelchairs are left with the inconvenience of not having an easy way to take their vital signs. Typically, patients are required to visit the hospital in order to take the vital signs. VitalGO is a wheel chair system that equipped with medical devices to take vital signs and then transmit data to a mobile application for convenient, long term health monitoring. The vital signs include oxygen saturation, heart rate, and blood pressure, breathing rate and body temperature. Oxygen saturation and heart rate are monitored through pulse oximeter. Blood pressure is taken through a radar sensor. Breathing rate is derived through thoracic impedance while body temperature is measured through an infrared thermometer. The application receives data through bluetooth and stores in a database for review in a simple graphical interface. The application will have the ability to display this data over various time intervals such as a day, week, month, 3 months, 6 months and a year. The final system for the mobile app can also provide an interface for both the user and their physician(s) to record notes or keep record of daily symptoms that a patient might be having. The user’s doctor will be granted access by the user to view the patient information for assistance with a more accurate diagnosis. Also, this wheelchair accessory conveniently includes a foldable table/desk as somewhere to place an electronic device that may be used to access the app. The foldable table will overall contribute to the wheelchair user’s increased comfort and will give them somewhere to place food, a book, or any other form of entertainment that would normally be hard to juggle on their lap.Keywords: wheel chair, vital sign, mobile application, telemedicine
Procedia PDF Downloads 3314415 Appropriate Technology: Revisiting the Movement in Developing Countries for Sustainability
Authors: Jayshree Patnaik, Bhaskar Bhowmick
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The economic growth of any nation is steered and dependent on innovation in technology. It can be preferably argued that technology has enhanced the quality of life. Technology is linked both with an economic and a social structure. But there are some parts of the world or communities which are yet to reap the benefits of technological innovation. Business and organizations are now well equipped with cutting-edge innovations that improve the firm performance and provide them with a competitive edge, but rarely does it have a positive impact on any community which is weak and marginalized. In recent times, it is observed that communities are actively handling social or ecological issues with the help of indigenous technologies. Thus, "Appropriate Technology" comes into the discussion, which is quite prevalent in the rural third world. Appropriate technology grew as a movement in the mid-1970s during the energy crisis, but it lost its stance in the following years when people started it to describe it as an inferior technology or dead technology. Basically, there is no such technology which is inferior or sophisticated for a particular region. The relevance of appropriate technology lies in penetrating technology into a larger and weaker section of community where the “Bottom of the pyramid” can pay for technology if they find the price is affordable. This is a theoretical paper which primarily revolves around how appropriate technology has faded and again evolved in both developed and developing countries. The paper will try to focus on the various concepts, history and challenges faced by the appropriate technology over the years. Appropriate technology follows a documented approach but lags in overall design and diffusion. Diffusion of technology into the poorer sections of community remains unanswered until the present time. Appropriate technology is multi-disciplinary in nature; therefore, this openness allows having a varied working model for different problems. Appropriate technology is a friendly technology that seeks to improve the lives of people in a constraint environment by providing an affordable and sustainable solution. Appropriate technology needs to be defined in the era of modern technological advancement for sustainability.Keywords: appropriate technology, community, developing country, sustainability
Procedia PDF Downloads 2624414 A Hybrid Multi-Criteria Hotel Recommender System Using Explicit and Implicit Feedbacks
Authors: Ashkan Ebadi, Adam Krzyzak
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Recommender systems, also known as recommender engines, have become an important research area and are now being applied in various fields. In addition, the techniques behind the recommender systems have been improved over the time. In general, such systems help users to find their required products or services (e.g. books, music) through analyzing and aggregating other users’ activities and behavior, mainly in form of reviews, and making the best recommendations. The recommendations can facilitate user’s decision making process. Despite the wide literature on the topic, using multiple data sources of different types as the input has not been widely studied. Recommender systems can benefit from the high availability of digital data to collect the input data of different types which implicitly or explicitly help the system to improve its accuracy. Moreover, most of the existing research in this area is based on single rating measures in which a single rating is used to link users to items. This paper proposes a highly accurate hotel recommender system, implemented in various layers. Using multi-aspect rating system and benefitting from large-scale data of different types, the recommender system suggests hotels that are personalized and tailored for the given user. The system employs natural language processing and topic modelling techniques to assess the sentiment of the users’ reviews and extract implicit features. The entire recommender engine contains multiple sub-systems, namely users clustering, matrix factorization module, and hybrid recommender system. Each sub-system contributes to the final composite set of recommendations through covering a specific aspect of the problem. The accuracy of the proposed recommender system has been tested intensively where the results confirm the high performance of the system.Keywords: tourism, hotel recommender system, hybrid, implicit features
Procedia PDF Downloads 2724413 Reimagining the Management of Telco Supply Chain with Blockchain
Authors: Jeaha Yang, Ahmed Khan, Donna L. Rodela, Mohammed A. Qaudeer
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Traditional supply chain silos still exist today due to the difficulty of establishing trust between various partners and technological barriers across industries. Companies lose opportunities and revenue and inadvertently make poor business decisions resulting in further challenges. Blockchain technology can bring a new level of transparency through sharing information with a distributed ledger in a decentralized manner that creates a basis of trust for business. Blockchain is a loosely coupled, hub-style communication network in which trading partners can work indirectly with each other for simpler integration, but they work together through the orchestration of their supply chain operations under a coherent process that is developed jointly. A Blockchain increases efficiencies, lowers costs, and improves interoperability to strengthen and automate the supply chain management process while all partners share the risk. Blockchain ledger is built to track inventory lifecycle for supply chain transparency and keeps a journal of inventory movement for real-time reconciliation. State design patterns are used to capture the life cycle (behavior) of inventory management as a state machine for a common, transparent and coherent process which creates an opportunity for trading partners to become more responsive in terms of changes or improvements in process, reconcile discrepancies, and comply with internal governance and external regulations. It enables end-to-end, inter-company visibility at the unit level for more accurate demand planning with better insight into order fulfillment and replenishment.Keywords: supply chain management, inventory trace-ability, perpetual inventory system, inventory lifecycle, blockchain, inventory consignment, supply chain transparency, digital thread, demand planning, hyper ledger fabric
Procedia PDF Downloads 904412 A Review on Applications of Evolutionary Algorithms to Reservoir Operation for Hydropower Production
Authors: Nkechi Neboh, Josiah Adeyemo, Abimbola Enitan, Oludayo Olugbara
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Evolutionary algorithms are techniques extensively used in the planning and management of water resources and systems. It is useful in finding optimal solutions to water resources problems considering the complexities involved in the analysis. River basin management is an essential area that involves the management of upstream, river inflow and outflow including downstream aspects of a reservoir. Water as a scarce resource is needed by human and the environment for survival and its management involve a lot of complexities. Management of this scarce resource is necessary for proper distribution to competing users in a river basin. This presents a lot of complexities involving many constraints and conflicting objectives. Evolutionary algorithms are very useful in solving this kind of complex problems with ease. Evolutionary algorithms are easy to use, fast and robust with many other advantages. Many applications of evolutionary algorithms, which are population based search algorithm, are discussed. Different methodologies involved in the modeling and simulation of water management problems in river basins are explained. It was found from this work that different evolutionary algorithms are suitable for different problems. Therefore, appropriate algorithms are suggested for different methodologies and applications based on results of previous studies reviewed. It is concluded that evolutionary algorithms, with wide applications in water resources management, are viable and easy algorithms for most of the applications. The results suggested that evolutionary algorithms, applied in the right application areas, can suggest superior solutions for river basin management especially in reservoir operations, irrigation planning and management, stream flow forecasting and real-time applications. The future directions in this work are suggested. This study will assist decision makers and stakeholders on the best evolutionary algorithm to use in varied optimization issues in water resources management.Keywords: evolutionary algorithm, multi-objective, reservoir operation, river basin management
Procedia PDF Downloads 4914411 Study of Laminar Convective Heat Transfer, Friction Factor, and Pumping Power Advantage of Aluminum Oxide-Water Nanofluid through a Channel
Authors: M. Insiat Islam Rabby, M. Mahbubur Rahman, Eshanul Islam, A. K. M. Sadrul Islam
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The numerical and simulative analysis of laminar heat exchange convection of aluminum oxide (Al₂O₃) - water nanofluid for the developed region through two parallel plates is presented in this present work. The second order single phase energy equation, mass and momentum equation are solved by using finite volume method with the ANSYS FLUENT 16 software. The distance between two parallel plates is 4 mm and length is 600 mm. Aluminum oxide (Al₂O₃) is used as nanoparticle and water is used as the base/working fluid for the investigation. At the time of simulation 1% to 5% volume concentrations of the Al₂O₃ nanoparticles are used for mixing with water to produce nanofluid and a wide range of interval of Reynolds number from 500 to 1100 at constant heat flux 500 W/m² at the channel wall has also been introduced. The result reveals that for increasing the Reynolds number the Nusselt number and heat transfer coefficient are increased linearly and friction factor decreased linearly in the developed region for both water and Al₂O₃-H₂O nanofluid. By increasing the volume fraction of Al₂O₃-H₂O nanofluid from 1% to 5% the value of Nusselt number increased rapidly from 0.7 to 7.32%, heat transfer coefficient increased 7.14% to 31.5% and friction factor increased very little from 0.1% to 4% for constant Reynolds number compared to pure water. At constant heat transfer coefficient 700 W/m2-K the pumping power advantages have been achieved 20% for 1% volume concentration and 62% for 3% volume concentration of nanofluid compared to pure water.Keywords: convective heat transfer, pumping power, constant heat flux, nanofluid, nanoparticles, volume concentration, thermal conductivity
Procedia PDF Downloads 1594410 Toxicity, Analgesic, and Anti-Pyretic Activities of Methanolic Extract from Hyoscyamus albus’ Leaves in Albinos Rats
Authors: Yahia Massinissa, Afaf Benhouda, Mouloud Yahia
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Objective: The aim of this study was to investigate the toxicity; analgesic and anti-pyretic properties of standardized HA methanolic extract (HAMeOH) in vivo. Methods: The acute toxicity study was performed on rats while adopting the OECD-420 Guidelines (fixed dose procedure). Assessment of analgesic activity was performed in rats with two analgesic models. One was acetic acid induced writhing response and the other formalin-induced paw licking. The anti-pyretic effect was tested by Brewer’s yeast induced fever in rats. Results: For the acute toxicity test, the higher dose administration of 2000 mg/kg bw. of H.albus did not produce any toxic signs or deaths in rats. There were no significant differences (p>0.05) in the body and organ weights between control and treated groups. The (LD50) of 'H. albus' was higher than 2000 g/kg bw. In subacute toxicity study, no mortality and toxic signs were observed with the doses of 100 and 200 mg/kg bw. of extracts of for 28 consecutive days. These analgesic experimental results indicated that HAMeOH (100 mg/kg and 200 mg/kg) decreased the acetic acid-induced writhing responses and HAMeOH (100 mg/kg and 200 mg/kg) decreased the licking time in the second phase of the formalin test. Moreover, in the model of yeast-induced elevation of the body temperature HAMeOH showed dose-dependent lowering of the body temperature up to 3h at both the doses these results obtained, were comparable to that of paracetamol. Conclusion: The present findings indicate that the leaves of Hyoscyamus albus L. possess potent analgesic and antipyretic activity.Keywords: Hyoscyamus albus, Umbilicus rupestris, secondary metabolites, NMR with protons, pharmacobiologic activities, methanolic extract
Procedia PDF Downloads 4234409 Rational Thinking and Forgiveness in Pakistan: The Role of Democratic Values and Mass Media Attitude
Authors: Muhammad Shoaib
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Every society has a set of beliefs, norms, values, folkways, mores and laws. All the principles, customs, traditions and procedures of societies are directly or indirectly related to the religion of the society and changed with the passage of time by the mediation of democratic values attitudes and mass media influence. The main objective of the present study is to examine the effects of rational thinking values on forgiveness attitude by the mediation of democratic values and mass media attitude among family members. As many other developing settings, Pakistani society is undergoing a rapid and multifaceted social change, in which traditional thinking coexists and often clashes with modern thinking. Rational thinking attitude has great effects on the forgiveness attitude among family members as well as all the members of Pakistani society. For the present study 520 respondents were sampled from two urban areas of Punjab province; Lahore and Faisalabad, through proportionate random sampling technique. A survey method was used as a technique of data collection and an interview schedule was administered to collect information from the respondents. The results support that the net of other factors, favorable democratic values attitudes are positively associated rational thinking attitudes. The results also provide support that all other things equal, mass media attitudes also have a significant positive effect on rational thinking attitudes. Favorable democratic values attitudes have a significant net positive effect and the effect of mass media attitudes is positive and statistically highly significant. It shows that the effects of both democratic values attitudes and mass media attitudes diminish in magnitude when the rational thinking attitudes scale is included. However, the effect of democratic values remains highly significant. In comparison, the effect of mass media attitudes is only marginally significant.Keywords: rationality, forgiveness, democratic values, mass media, attitudes, Pakistan
Procedia PDF Downloads 3674408 An Analysis on Clustering Based Gene Selection and Classification for Gene Expression Data
Authors: K. Sathishkumar, V. Thiagarasu
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Due to recent advances in DNA microarray technology, it is now feasible to obtain gene expression profiles of tissue samples at relatively low costs. Many scientists around the world use the advantage of this gene profiling to characterize complex biological circumstances and diseases. Microarray techniques that are used in genome-wide gene expression and genome mutation analysis help scientists and physicians in understanding of the pathophysiological mechanisms, in diagnoses and prognoses, and choosing treatment plans. DNA microarray technology has now made it possible to simultaneously monitor the expression levels of thousands of genes during important biological processes and across collections of related samples. Elucidating the patterns hidden in gene expression data offers a tremendous opportunity for an enhanced understanding of functional genomics. However, the large number of genes and the complexity of biological networks greatly increase the challenges of comprehending and interpreting the resulting mass of data, which often consists of millions of measurements. A first step toward addressing this challenge is the use of clustering techniques, which is essential in the data mining process to reveal natural structures and identify interesting patterns in the underlying data. This work presents an analysis of several clustering algorithms proposed to deals with the gene expression data effectively. The existing clustering algorithms like Support Vector Machine (SVM), K-means algorithm and evolutionary algorithm etc. are analyzed thoroughly to identify the advantages and limitations. The performance evaluation of the existing algorithms is carried out to determine the best approach. In order to improve the classification performance of the best approach in terms of Accuracy, Convergence Behavior and processing time, a hybrid clustering based optimization approach has been proposed.Keywords: microarray technology, gene expression data, clustering, gene Selection
Procedia PDF Downloads 3234407 Software Development for AASHTO and Ethiopian Roads Authority Flexible Pavement Design Methods
Authors: Amare Setegn Enyew, Bikila Teklu Wodajo
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The primary aim of flexible pavement design is to ensure the development of economical and safe road infrastructure. However, failures can still occur due to improper or erroneous structural design. In Ethiopia, the design of flexible pavements relies on doing calculations manually and selecting pavement structure from catalogue. The catalogue offers, in eight different charts, alternative structures for combinations of traffic and subgrade classes, as outlined in the Ethiopian Roads Authority (ERA) Pavement Design Manual 2001. Furthermore, design modification is allowed in accordance with the structural number principles outlined in the AASHTO 1993 Guide for Design of Pavement Structures. Nevertheless, the manual calculation and design process involves the use of nomographs, charts, tables, and formulas, which increases the likelihood of human errors and inaccuracies, and this may lead to unsafe or uneconomical road construction. To address the challenge, a software called AASHERA has been developed for AASHTO 1993 and ERA design methods, using MATLAB language. The software accurately determines the required thicknesses of flexible pavement surface, base, and subbase layers for the two methods. It also digitizes design inputs and references like nomographs, charts, default values, and tables. Moreover, the software allows easier comparison of the two design methods in terms of results and cost of construction. AASHERA's accuracy has been confirmed through comparisons with designs from handbooks and manuals. The software can aid in reducing human errors, inaccuracies, and time consumption as compared to the conventional manual design methods employed in Ethiopia. AASHERA, with its validated accuracy, proves to be an indispensable tool for flexible pavement structure designers.Keywords: flexible pavement design, AASHTO 1993, ERA, MATLAB, AASHERA
Procedia PDF Downloads 634406 Application of Customized Bioaugmentation Inocula to Alleviate Ammonia Toxicity in CSTR Anaerobic Digesters
Authors: Yixin Yan, Miao Yan, Irini Angelidaki, Ioannis Fotidis
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Ammonia, which derives from the degradation of urea and protein-substrates, is the major toxicant of the commercial anaerobic digestion reactors causing loses of up to 1/3 of their practical biogas production, which reflects directly on the overall revenue of the plants. The current experimental work is aiming to alleviate the ammonia inhibition in anaerobic digestion (AD) process by developing an innovative bioaugmentation method of ammonia tolerant methanogenic consortia. The ammonia tolerant consortia were cultured in batch reactors and immobilized together with biochar in agar (customized inocula). Three continuous stirred-tank reactors (CSTR), fed with the organic fraction of municipal solid waste at a hydraulic retention time of 15 days and operated at thermophilic (55°C) conditions were assessed. After an ammonia shock of 4 g NH4+-N L-1, the customized inocula were bioaugmented into the CSTR reactors to alleviate ammonia toxicity effect on AD process. Recovery rate of methane production and methanogenic activity will be assessed to evaluate the bioaugmentation performance, while 16s rRNA gene sequence will be used to reveal the difference of microbial community changes through bioaugmentation. At the microbial level, the microbial community structures of the four reactors will be analysed to find the mechanism of bioaugmentation. Changes in hydrogen formation potential will be used to predict direct interspecies electron transfer (DIET) between ammonia tolerant methanogens and syntrophic bacteria. This experimental work is expected to create bioaugmentation inocula that will be easy to obtain, transport, handled and bioaugment in AD reactors to efficiently alleviate the ammonia toxicity, without alternating any of the other operational parameters including the ammonia-rich feedstocks.Keywords: artisanal fishing waste, acidogenesis, volatile fatty acids, pH, inoculum/substrate ratio
Procedia PDF Downloads 1274405 Comparative Efficacy of Pomegranate Juice, Peel and Seed Extract in the Stabilization of Corn Oil under Accelerated Conditions
Authors: Zoi Konsoula
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Antioxidant-rich extracts were prepared from pomegranate peels, seeds and juice using methanol and ethanol and their antioxidant activity was evaluated by the 1,1-diphenyl-2-picrylhydrazine (DPPH) radical scavenging and Ferric Reducing Antioxidant Power (FRAP) method. Both analytical methods indicated a higher antioxidant activity in extracts prepared from peels, which was comparable to that of butylated hydroxytoluene (BHT). Furthermore, the antioxidant activity was correlated to the phenolic and flavonoid content of the various extracts. The antioxidant effectiveness of the extracts was also assessed using corn oil as the oxidation substrate. More specifically, preheated corn oil samples stabilized with extracts at a concentration of 250 ppm, 500 ppm or 1,000 ppm were subjected to accelerated aging (100 oC, 10 days) and the extent of oxidative alteration was followed by the measurement of the peroxide, conjugated dienes and trienes, as well as p-aniside value. BHT at its legal limit (200 ppm) served as standard besides the control sample. Results from the different parameters were in agreement with each other suggesting that pomegranate extracts can stabilize corn oil effectively under accelerated conditions, at all concentrations tested. However, the magnitude of oil stabilization depended strongly on the amount of extract added and this was positively correlated with their phenolic content. Pomegranate peel extracts, which exhibited the highest not only phenolic and flavonoid content but also antioxidant activity, were more potent in inhibiting oxidative deterioration. Both methanolic and ethanolic peel extracts at a concentration of 500 ppm exerted a stabilizing effect comparable to that of BHT, while at a concentration of 1000 ppm they exhibited higher stabilization efficiency in comparison to BHT. Finally, heating oil samples resulted in a time dependent decrease in their antioxidant capacity. Samples containing peel extracts appeared to retain their antioxidant capacity for a longer period, indicating that these extracts contained active compounds that offered superior antioxidant protection to corn oil.Keywords: antioxidant activity, corn oil, oxidative deterioration, pomegranate
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